The present invention relates generally to the field of power electronic devices such as those used in power conversion or application of power to motors and similar loads. More particularly, the present invention relates to systems and methods for using multiple 18-pulse rectifier circuits in parallel to increase the overall rating of a motor drive while reducing the input current harmonics.
Power electronic devices and modules are used in a wide range of applications. For example, electric motor controllers, rectifiers, inverters, and more generally, power converters are employed to condition incoming power and supply power to devices, such as a drive motor. However, the power and signals transmitted within the electronic devices often contain undesirable characteristics that may require additional devices to reduce or filter the signals. For instance, in alternating current (AC) motor controllers, a rectifier may be used to covert the AC power to stable direct current (DC) power, and an inverter circuit may be used to convert the stable DC power back to the AC power supplied to the motor. However, rectifiers may be susceptible to AC input current harmonics and DC bus ripple, among other things.